package chapter10.demo1;
import java.sql.*;
import java.util.Scanner;

public class Demo1 {
    public static void main(String[] args) throws SQLException {
        //修改用户和密码
        /**
         * 1.注册驱动
         * 2.获取连接
         * 3.创建Statement对象
         * 4.执行SQL语句
         * 5.操作结果
         * 6.关闭连接
         */
        Statement stmt=null;
        ResultSet rs=null;
        Connection conn=null;
        try {
            //1.注册数据库的驱动
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2.通过DriverManager获取数据库连接
            String  url="jdbc:mysql://localhost:3306/jdbc?serverTimezone=GMT%2B8&useSSL=false";
            String username="root";
            String password="123456";
            conn=DriverManager.getConnection(url,username,password);
           /**
           *静态SQL语句用Statement
           *动态SQL语句用PreparedStatement
            */
            Scanner sc = new Scanner(System.in);
            System.out.println("请输入你的旧账号名：");
            String n1 = sc.next();
            System.out.println("请输入你的旧密码：");
            String p1 = sc.next();
            System.out.println("请输入你的新账号名：");
            String n2 = sc.next();
            System.out.println("请输入你的新密码：");
            String p2 = sc.next();


            String updateSQL = "update users set name=?,  password=? where name=? and password=?";
            PreparedStatement ps = conn.prepareStatement(updateSQL);
            ps.setString(1,n2);
            ps.setString(2,p2);
            ps.setString(3,n1);
            ps.setString(4,p1);
            int res = ps.executeUpdate();
            //5.操作ResultSet结果集
            System.out.println(res);
//            if (res>0){
//                System.out.println("账号密码更新成功");
//            }else{
//                System.out.println("账号密码更新失败");
//            }
        }catch (ClassNotFoundException e){
            e.printStackTrace();
        }finally{
            //6.回收资源
            if(rs !=null){
                try{
                    rs.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
                rs=null;
            }
            if(stmt !=null){
                try{
                    stmt.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
                stmt=null;
            }
            if(conn !=null){
                try{
                    conn.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
                conn=null;
            }
        }
    }
}
